Once you hear about the five life stages of happiness, they make sense. Sometimes it's the way things are said that finally makes it connect; the choice of words and just packaging something up as one complete thought. Which is what happened nicely in this piece.
It's even better to take away the ages. Most people are in one stage and it may not line up with the ages in the video. And that's okay, isn't it?
The helpful thing is that someone has packaged it all up in a very nice, and logical, way.